Preserved structural connectivity mediates the clinical effect of thrombolysis in patients with anterior-circulation stroke

Thrombolysis with recombinant tissue plasminogen activator in acute ischemic stroke aims to restore compromised blood flow and prevent further neuronal damage. Despite the proven clinical efficacy of this treatment, little is known about the short-term effects of systemic thrombolysis on structural brain connectivity. In this secondary analysis of the WAKE-UP trial, we used MRI-derived measures of infarct size and estimated structural network disruption to establish that thrombolysis is associated not only with less infarct growth, but also with reduced loss of large-scale connectivity between grey-matter areas after stroke. In a causal mediation analysis, infarct growth mediated a non-significant 8.3% (CI95% [-8.0, 32.6]%) of the clinical effect of thrombolysis on functional outcome. The proportion mediated jointly through infarct growth and change of structural connectivity, especially in the border zone around the infarct core, however, was as high as 33.4% (CI95% [8.8, 77.4]%). Preservation of structural connectivity is thus an important determinant of treatment success and favourable functional outcome in addition to lesion volume. It might, in the future, serve as an imaging endpoint in clinical trials or as a target for therapeutic interventions.

Early parietofrontal network upregulation relates to future persistent deficits after severe stroke-a prospective cohort study

Recent brain imaging has evidenced that parietofrontal networks show alterations after stroke which also relate to motor recovery processes. There is converging evidence for an upregulation of parietofrontal coupling between parietal brain regions and frontal motor cortices. The majority of studies though have included only moderately to mildly affected patients, particularly in the subacute or chronic stage. Whether these network alterations will also be present in severely affected patients and early after stroke and whether such information can improve correlative models to infer motor recovery remains unclear. In this prospective cohort study, 19 severely affected first-ever stroke patients (mean age 74 years, 12 females) were analysed which underwent resting-state functional MRI and clinical testing during the initial week after the event. Clinical evaluation of neurological and motor impairment as well as global disability was repeated after three and six months. Nineteen healthy participants of similar age and gender were also recruited. MRI data were used to calculate functional connectivity values between the ipsilesional primary motor cortex, the ventral premotor cortex, the supplementary motor area and the anterior and caudal intraparietal sulcus of the ipsilesional hemisphere. Linear regression models were estimated to compare parietofrontal functional connectivity between stroke patients and healthy controls and to relate them to motor recovery. The main finding was a significant increase in ipsilesional parietofrontal coupling between anterior intraparietal sulcus and the primary motor cortex in severely affected stroke patients (P < 0.003). This upregulation significantly contributed to correlative models explaining variability in subsequent neurological and global disability as quantified by National Institute of Health Stroke Scale and modified Rankin Scale, respectively. Patients with increased parietofrontal coupling in the acute stage showed higher levels of persistent deficits in the late subacute stage of recovery (P < 0.05). This study provides novel insights that parietofrontal networks of the ipsilesional hemisphere undergo neuroplastic alteration already very early after severe motor stroke. The association between early parietofrontal upregulation and future levels of persistent functional deficits and dependence from help in daily living might be useful in models to enhance clinical neurorehabilitative decision making.

Dysphagia Screening in Parkinson's Disease. A diagnostic accuracy cross-sectional study investigating the applicability of the Gugging Swallowing Screen (GUSS)

BACKGROUND

Simple water-swallowing screening tools are not predictive of aspiration and dysphagia in patients with Parkinson's Disease (PD). We investigated the diagnostic accuracy of a multi-texture screening tool, the Gugging Swallowing Screen (GUSS) to identify aspiration and dysphagia/penetration in PD patients compared to flexible endoscopic evaluation of swallowing (FEES).

METHODS

Swallowing function was evaluated in 51 PD participants in clinical 'on-medication' state with the GUSS and a FEES examination according to standardized protocols. Inter-rater reliability and convergent validity were determined and GUSS- and FEES-based diet recommendations were compared.

KEY RESULTS

Inter-rater reliability of GUSS ratings was high (r_s  = 0.8; p < 0.001). Aspiration was identified by the GUSS with a sensitivity of 50%, and specificity of 51.35% (PPV 28%, NPV 73%, LR+ 1.03, LR- 0.97), dysphagia/penetration was identified with 72.97% sensitivity and 35.71% specificity (PPV 75%, NPV 33.33%, LR+ 1.14, LR- 0.76). Agreement between GUSS- and FEES-based diet recommendations was low (r_s  = 0.12, p = 0.42) with consistent NPO (Nil per Os) allocation by GUSS and FEES in only one participant.

CONCLUSIONS AND INFERENCES

The multi-texture screening tool GUSS in its current form, although applicable with good inter-rater reliability, does not detect aspiration in PD patients with acceptable accuracy. Modifications of the GUSS parameters "coughing," "voice change" and "delayed swallowing" might enhance validity. The GUSS' diet recommendations overestimate the need for oral intake restriction in PD patients and should be verified by instrumental swallowing examination.

Strengthened structure-function relationships of the corticospinal tract by free water correction after stroke

The corticospinal tract is the most intensively investigated tract of the human motor system in stroke rehabilitative research. Diffusion-tensor-imaging gives insights into its microstructure, and transcranial magnetic stimulation assesses its excitability. Previous data on the interrelationship between both measures are contradictory. Correlative or predictive models which associate them with motor outcome are incomplete. Free water correction has been developed to enhance diffusion-tensor-imaging by eliminating partial volume with extracellular water, which could improve capturing stroke-related microstructural alterations, thereby also improving structure-function relationships in clinical cohorts. In the present cross-sectional study, data of 18 chronic stroke patients and 17 healthy controls, taken from a previous study on cortico-cerebellar motor tracts, were re-analysed: The data included diffusion-tensor-imaging data quantifying corticospinal tract microstructure with and without free water correction, transcranial magnetic stimulation data assessing recruitment curve properties of motor evoked potentials and detailed clinical data. Linear regression modelling was used to interrelate corticospinal tract microstructure, recruitment curves properties and clinical scores. The main finding of the present study was that free water correction substantially strengthens structure-function associations in stroke patients: Specifically, our data evidenced a significant association between fractional anisotropy of the ipsilesional corticospinal tract and its excitability (P = 0.001, adj. R² = 0.54), with free water correction explaining additional 20% in recruitment curve variability. For clinical scores, only free water correction leads to the reliable detection of significant correlations between ipsilesional corticospinal tract fractional anisotropy and residual grip (P = 0.001, adj. R² = 0.70) and pinch force (P < 0.001, adj. R² = 0.72). Finally, multimodal models can be improved by free water correction as well. This study evidences that corticospinal tract microstructure directly relates to its excitability in stroke patients. It also shows that unexplained variance in motor outcome is considerably reduced by free water correction arguing that it might serve as a powerful tool to improve existing models of structure-function associations and potentially also outcome prediction after stroke.

White matter integrity and structural brain network topology in cerebral small vessel disease: The Hamburg city health study

Cerebral small vessel disease is a common finding in the elderly and associated with various clinical sequelae. Previous studies suggest disturbances in the integration capabilities of structural brain networks as a mediating link between imaging and clinical presentations. To what extent cerebral small vessel disease might interfere with other measures of global network topology is not well understood. Connectomes were reconstructed via diffusion weighted imaging in a sample of 930 participants from a population based epidemiologic study. Linear models were fitted testing for an association of graph-theoretical measures reflecting integration and segregation with both the Peak width of Skeletonized Mean Diffusivity (PSMD) and the load of white matter hyperintensities of presumed vascular origin (WMH). The latter were subdivided in periventricular and deep for an analysis of localisation-dependent correlations of cerebral small vessel disease. The median WMH volume was 0.6 mL (1.4) and the median PSMD 2.18 mm2 /s x 10-4 (0.5). The connectomes showed a median density of 0.880 (0.030), the median values for normalised global efficiency, normalised clustering coefficient, modularity Q and small-world propensity were 0.780 (0.045), 1.182 (0.034), 0.593 (0.026) and 0.876 (0.040) respectively. An increasing burden of cerebral small vessel disease was significantly associated with a decreased integration and increased segregation and thus decreased small-worldness of structural brain networks. Even in rather healthy subjects increased cerebral small vessel disease burden is accompanied by topological brain network disturbances. Segregation parameters and small-worldness might as well contribute to the understanding of the known clinical sequelae of cerebral small vessel disease.

Trimethyllysine, vascular risk factors and outcome in acute ischemic stroke (MARK-STROKE)

Trimethyllysine (TML) is involved in the generation of the pro-atherogenic metabolite trimethylamine-N-oxide (TMAO) by gut microbiota. In clinical studies, elevated TML levels predicted major adverse cardiovascular events (MACE) in patients with acute or stable coronary artery disease (CAD). In contrast to cardiovascular patients, the role of TML in patients with acute cerebral ischemia is unknown. Here, we evaluated circulating TML levels in 374 stroke patients from the prospective biomarkers in stroke (MARK-STROKE) study. Compared with 167 matched healthy controls, acute ischemic stroke patients had lower median TML plasma concentrations, i.e. 0.71 vs. 0.47 µmol/L (p < 0.001) and this difference persisted after adjusting for age and sex. TML plasma concentrations were associated with age, serum creatinine, glucose, cholesterol and lysine. Patients with prevalent arterial hypertension, atrial fibrillation or a history of myocardial infarction had increased TML levels, but this observation was not independent of age, sex and GFR. In 274 patients, follow-up data were available. During a median follow-up of 284 [25th-75th percentile: 198, 431] days, TML was not associated with incident MACE (stroke, myocardial infarction, death). In summary, our data suggests a different role of TML in acute ischemic stroke compared with CAD patients.

Effect of intravenous alteplase on post-stroke depression in the WAKE UP trial

BACKGROUND AND PURPOSE

The aim was to study the effect of intravenous alteplase on the development of post-stroke depression (PSD) in acute stroke patients, and to identify predictors of PSD.

METHODS

This post hoc analysis included patients with unknown onset stroke randomized to treatment with alteplase or placebo in the WAKE-UP trial (ClinicalTrials.gov number, NCT01525290), in whom a composite end-point of PSD was defined as a Beck Depression Inventory ≥10, medication with an antidepressant, or depression recorded as an adverse event. Multiple logistic regression was used to identify predictors of PSD at 90 days. Structural equation modelling was applied to assess the indirect effect of thrombolysis on PSD mediated by the modified Rankin Scale.

RESULTS

Information on the composite end-point was available for 438 of 503 randomized patients. PSD was present in 96 of 224 (42.9%) patients in the alteplase group and 115 of 214 (53.7%) in the placebo group (odds ratio 0.63; 95% confidence interval 0.43-0.94; p = 0.022; adjusted for age and National Institutes of Health Stroke Scale at baseline). Prognostic factors associated with PSD included baseline medication with antidepressants, higher lesion volume, history of depression and assignment to placebo. While 65% of the effect of thrombolysis on PSD were caused directly, 35% were mediated by an improvement of the mRS.

CONCLUSIONS

Treatment with alteplase in patients with acute stroke resulted in lower rates of depression at 90 days, which were only partially explained by reduced functional disability. Predictors of PSD including history and clinical characteristics may help in identifying patients at risk of PSD.

How Does SARS-CoV-2 Infection Affect Survival of Emergency Cardiovascular Patients? A Cohort Study From a German Insurance Claims Database

Objective

A previous study revealed a preliminary trend towards higher in hospital mortality in patients admitted as an emergency with acute stroke during the COVID-19 pandemic in Germany. The current study aimed to further examine the possible impact of a confirmed SARS-CoV-2 infection on in hospital mortality.

Methods

This was a retrospective analysis of health insurance claims data from the second largest insurance fund in Germany, BARMER. Patients hospitalised for ST elevation (STEMI) and non-ST elevation (NSTEMI) myocardial infarction, acute limb ischaemia (ALI), aortic rupture, acute stroke, or transient ischaemic attack (TIA) between 1 January 2017, and 31 October 2020, were included. Admission rates per 10 000 insured and mortality were compared between March − June 2017 – 2019 (pre-COVID) and March − June 2020 (COVID). Mortality rates were determined by the occurrence of a confirmed SARS-CoV-2 infection.

Results

A total of 316 718 hospitalisations were included (48.7% female, mean 72.5 years), and 21 191 (6.7%, 95% CI 6.6% – 6.8%) deaths occurred. In hospital mortality increased during the COVID-19 pandemic when compared with the three previous years for patients with acute stroke from 8.3% (95% CI 8.0 – 8.5) to 9.6% (95% CI 9.1 – 10.2), while no statistically significant changes were observed for STEMI, NSTEMI, ALI, aortic rupture, and TIA. When comparing patients with confirmed SARS-CoV-2 infection (2.4%, 95% CI 2.3 – 2.5) vs. non-infected patients, a higher in hospital mortality was observed for acute stroke (12.4% vs. 9.0%), ALI (14.3% vs. 5.0%), and TIA (2.7% vs. 0.3%), while no statistically significant differences were observed for STEMI, NSTEMI, and aortic rupture.

Conclusion

This retrospective analysis of claims data has provided hints of an association between the COVID-19 pandemic and increased in hospital mortality in patients with acute stroke. Furthermore, confirmed SARS-CoV-2 infection was associated with increased mortality in patients with stroke, TIA, and ALI. Future studies are urgently needed to better understand the underlying mechanism and relationship between the new coronavirus and acute stroke.

Association of lipid levels with motor and cognitive function and decline in advanced Parkinson's disease in the Mark-PD study

OBJECTIVES

In prospective cohort studies different blood lipid fractions have been identified as risk factors of Parkinson's disease (PD). However, data relating lipoproteins to disease phenotypes and progression in advanced PD patients are sparse. Therefore, we assessed the most common lipoproteins in a case-control design and evaluated their associations with motor and cognitive function and decline in PD patients.

METHODS

Triglycerides, LDL-cholesterol (LDL-C), HDL-cholesterol (HDL-C), apolipoprotein A1 (ApoA1), apolipoprotein B (ApoB), and lipoprotein a (Lp(a)) were analyzed in 294 PD patients of the MARK-PD study cohort and 588 controls matched for age, sex and cardiovascular risk factors. In PD patients, motor (MDS-UPDRS III, Hoehn-Yahr stage) and cognitive function (MoCA) were examined. In a sub-cohort (n = 98 patients), baseline lipid levels were correlated with motor and cognitive disease progression during a follow-up period of 523 ± 199 days.

RESULTS

At baseline, HDL-C levels were lower in PD patients compared to matched controls after adjustment. We observed a very weak association of Lp(a) levels with UDPRS III scores. In cross-sectional analyses, no other lipid fraction revealed a significant and consistent association with motor or cognitive function. During follow-up, no lipid fraction level was associated with motor or cognitive progression.

CONCLUSION

In advanced PD, there is no strong and consistent association of lipid levels with motor or cognitive function and decline.

Extent of FLAIR Hyperintense Vessels May Modify Treatment Effect of Thrombolysis: A Post hoc Analysis of the WAKE-UP Trial

Background and Aims: Fluid-attenuated inversion recovery (FLAIR) hyperintense vessels (FHVs) on MRI are a radiological marker of vessel occlusion and indirect sign of collateral circulation. However, the clinical relevance is uncertain. We explored whether the extent of FHVs is associated with outcome and how FHVs modify treatment effect of thrombolysis in a subgroup of patients with confirmed unilateral vessel occlusion from the randomized controlled WAKE-UP trial.

Methods: One hundred sixty-five patients were analyzed. Two blinded raters independently assessed the presence and extent of FHVs (defined as the number of slices with visible FHV multiplied by FLAIR slice thickness). Patients were then separated into two groups to distinguish between few and extensive FHVs (dichotomization at the median <30 or ≥30).

Results: Here, 85% of all patients (n = 140) and 95% of middle cerebral artery (MCA) occlusion patients (n = 127) showed FHVs at baseline. Between MCA occlusion patients with few and extensive FHVs, no differences were identified in relative lesion growth (p = 0.971) and short-term [follow-up National Institutes of Health Stroke Scale (NIHSS) score; p = 0.342] or long-term functional recovery [modified Rankin Scale (mRS) <2 at 90 days poststroke; p = 0.607]. In linear regression analysis, baseline extent of FHV (defined as a continuous variable) was highly associated with volume of hypoperfused tissue (β = 2.161; 95% CI 0.96–3.36; p = 0.001). In multivariable regression analysis adjusted for treatment group, stroke severity, lesion volume, occlusion site, and recanalization, FHV did not modify functional recovery. However, in patients with few FHVs, the odds for good functional outcome (mRS) were increased in recombinant tissue plasminogen activator (rtPA) patients compared to those who received placebo [odds ratio (OR) = 5.3; 95% CI 1.2–24.0], whereas no apparent benefit was observed in patients with extensive FHVs (OR = 1.1; 95% CI 0.3–3.8), p-value for interaction was 0.11.

Conclusion: While the extent of FHVs on baseline did not alter the evolution of stroke in terms of lesion progression or functional recovery, it may modify treatment effect and should therefore be considered relevant additional information in those patients who are eligible for intravenous thrombolysis.

Clinical Trial Registration: Main trial (WAKE-UP): ClinicalTrials.gov, NCT01525290; and EudraCT, 2011-005906-32. Registered February 2, 2012.

Rationale and design of an interventional study of cross-sectoral, coordinated treatment of stroke patients with patient-orientated outcome measurement (StroCare)

INTRODUCTION

Stroke has a long-term impact on functional status and quality of life in multiple health domains. A well-coordinated managed care program for stroke patients is crucial for ameliorating patients' health and cost-efficient use of resources. The aim of this study is the implementation and evaluation of an optimised cross-sectoral, coordinated and managed care program for stroke patients bridging secondary and tertiary care.

METHODS

In this multi-center mixed method sequentially controlled intervention study, stroke patients with ischemic stroke (I63), transient ischemic attack and related syndromes (G45), or intracerebral haermorrhage (I64) will be invited to participate. For a 12-months period, 235 consecutive patients are expected to be enrolled and assigned standard of care treatment as an active control group. During the following 12 months, 235 consecutive patients will be enrolled and assigned to a post stroke intervention program. The StroCare intervention consists of repeated outpatient visits with specialized stroke teams, the implementation of a case manager, the use of an electronical tool for communication between acute care, rehabilitation facilities, and out-patient care, and the definition of individualized treatment targets. Patients will be followed up for 24 months. The primary outcome is health-related quality of life measured by the Patient-Reported Outcomes Measurement Information System 10-Question Short Form (PROMIS-10) at 12 months after the index event, i.e. stroke or TIA. For the qualitative survey of the implementation process, 21 patients in the intervention group will be interviewed after implementation of the interventions. In addition, 20 health care providers and staff members will be interviewed before and after implementation. Additionally, economic outcomes will be evaluated after 6 and 12 months.

PERSPECTIVE

The study will not only provide information about the tested intervention but is likely to be helpful for clinicians, suppliers of reimbursement, and researchers in implementing and evaluating complex interventions in stroke care in general. With this program, the health care system will have a reference model at its disposal for transfer to other regions and settings.

TRIAL REGISTRATION

The trial is registered at ClinicalTrials.gov ( NCT04159324 ). Approval of the local ethics committee (Ethik-Kommission der Ärztekammer Hamburg, Niedersachsen, Schleswig-Holstein) has been obtained.

[Artificial intelligence in neurocritical care]

Artificial intelligence (AI) has been introduced into medicine and an AI-assisted medicine will be the future that we should help to shape. In particular, supervised, unsupervised, and reinforcement learning will be the main methods to play a role in the implementation of AI. Severely ill patients admitted to the intensive care unit (ICU) are closely monitored in order to be able to quickly respond to any changes. These monitoring data can be used to train AI models to predict critical phases in advance, making an earlier reaction possible. To achieve this a large amount of clinical data are needed in order to train models and an external validation on independent cohorts should take place. Prospective studies with treatment of patients admitted to the ICU with AI assistance should show that they provide a benefit for patients. We present the most important resources from de-identified (anonymized) patient data on open-source use for AI research in intensive care medicine. The focus is on neurological diseases in the ICU, therefore, we provide an overview of existing models for prediction of outcome, vasospasms, intracranial pressure and levels of consciousness. To introduce the advantages of AI in the clinical routine, more AI-based models with larger datasets will be needed. To achieve this international cooperation is absolutely necessary. Clinical centers associated with universities are needed to provide a constant validation of applied models as these models can change during use or a bias can develop during the training. A strong commitment to AI research is important for Germany, not only with respect to academic achievements but also in the light of a rapidly growing influence of AI on the economy.

Crossmodal Pattern Discrimination in Humans and Robots: A Visuo-Tactile Case Study

The quality of crossmodal perception hinges on two factors: The accuracy of the independent unimodal perception and the ability to integrate information from different sensory systems. In humans, the ability for cognitively demanding crossmodal perception diminishes from young to old age. Here, we propose a new approach to research to which degree the different factors contribute to crossmodal processing and the age-related decline by replicating a medical study on visuo-tactile crossmodal pattern discrimination utilizing state-of-the-art tactile sensing technology and artificial neural networks (ANN). We implemented two ANN models to specifically focus on the relevance of early integration of sensory information during the crossmodal processing stream as a mechanism proposed for efficient processing in the human brain. Applying an adaptive staircase procedure, we approached comparable unimodal classification performance for both modalities in the human participants as well as the ANN. This allowed us to compare crossmodal performance between and within the systems, independent of the underlying unimodal processes. Our data show that unimodal classification accuracies of the tactile sensing technology are comparable to humans. For crossmodal discrimination of the ANN the integration of high-level unimodal features on earlier stages of the crossmodal processing stream shows higher accuracies compared to the late integration of independent unimodal classifications. In comparison to humans, the ANN show higher accuracies than older participants in the unimodal as well as the crossmodal condition, but lower accuracies than younger participants in the crossmodal task. Taken together, we can show that state-of-the-art tactile sensing technology is able to perform a complex tactile recognition task at levels comparable to humans. For crossmodal processing, human inspired early sensory integration seems to improve the performance of artificial neural networks. Still, younger participants seem to employ more efficient crossmodal integration mechanisms than modeled in the proposed ANN. Our work demonstrates how collaborative research in neuroscience and embodied artificial neurocognitive models can help to derive models to inform the design of future neurocomputational architectures.

Sex Differences in Outcome After Thrombectomy for Acute Ischemic Stroke are Explained by Confounding Factors

PURPOSE

The aim of this study was to analyze sex differences in outcome after thrombectomy for acute ischemic stroke in clinical practice in a large prospective multicenter registry.

METHODS

Data of consecutive stroke patients treated with thrombectomy (June 2015-April 2018) derived from an industry-independent registry (German Stroke Registry-Endovascular Treatment) were prospectively analyzed. Multivariable binary logistic regression analyses were applied to determine whether sex is a predictor of functional independence outcome (defined as a modified Rankin scale [mRS] 0-2) 90 days after stroke.

RESULTS

In total, 2316 patients were included in the analysis, 1170 (50.5%) were female and 1146 (49.5%) were male. Women were older (median age 78 vs. 72 years; p < 0.001) and more frequently had a prestroke functional impairment defined by mRS >1 (24.8% vs. 14.1%; p < 0.001). In unadjusted analyses, independent outcome at 90 days was less frequent in women (33.2%) than men (40.6%; p < 0.001). Likewise, mortality was higher in women than in men (30.7% vs. 26.4%; p = 0.024). In adjusted regression analyses, however, sex was not associated with outcome. Lower age, a lower baseline National Institutes of Health Stroke Scale score, a higher Alberta Stroke Program Early CT score, prestroke functional independence, successful reperfusion, and concomitant intravenous thrombolysis therapy predicted independent outcome.

CONCLUSION

Women showed a worse functional outcome after thrombectomy for acute ischemic stroke in clinical practice; however, after adjustment for crucial confounders sex was not a predictor of outcome. The difference in outcome thus appears to result from differences in confounding factors such as age and prestroke functional status.

Safety and efficacy of intravenous thrombolysis in stroke patients on prior antiplatelet therapy in the WAKE-UP trial

Background

One quarter to one third of patients eligible for systemic thrombolysis are on antiplatelet therapy at presentation. In this study, we aimed to assess the safety and efficacy of intravenous thrombolysis in stroke patients on prescribed antiplatelet therapy in the WAKE-UP trial.

Methods

WAKE-UP was a multicenter, randomized, double-blind, placebo-controlled clinical trial to study the efficacy and safety of MRI-guided intravenous thrombolysis with alteplase in patients with an acute stroke of unknown onset time. The medication history of all patients randomized in the WAKE-UP trial was documented. The primary safety outcome was any sign of hemorrhagic transformation on follow-up MRI. The primary efficacy outcome was favorable functional outcome defined by a score of 0–1 on the modified Rankin scale at 90 days after stroke, adjusted for age and baseline stroke severity. Logistic regression models were fitted to study the association of prior antiplatelet treatment with outcome and treatment effect of intravenous alteplase.

Results

Of 503 randomized patients, 164 (32.6%) were on antiplatelet treatment. Patients on antiplatelet treatment were older (70.3 vs. 62.8 years, p <  0.001), and more frequently had a history of hypertension, atrial fibrillation, diabetes, hypercholesterolemia, and previous stroke or transient ischaemic attack. Rates of symptomatic intracranial hemorrhage and hemorrhagic transformation on follow-up imaging did not differ between patients with and without antiplatelet treatment. Patients on prior antiplatelet treatment were less likely to achieve a favorable outcome (37.3% vs. 52.6%, p = 0.014), but there was no interaction of prior antiplatelet treatment with intravenous alteplase concerning favorable outcome (p = 0.355). Intravenous alteplase was associated with higher rates of favorable outcome in patients on prior antiplatelet treatment with an adjusted odds ratio of 2.106 (95% CI 1.047–4.236).

Conclusions

Treatment benefit of intravenous alteplase and rates of post-treatment hemorrhagic transformation were not modified by prior antiplatelet intake among MRI-selected patients with unknown onset stroke. Worse functional outcome in patients on antiplatelets may result from a higher load of cardiovascular co-morbidities in these patients.

Symptoms and probabilistic anatomical mapping of lacunar infarcts

Background

The anatomical distribution of acute lacunar infarcts has mainly been studied for supratentorial lesions. In addition, little is known about the association with distinct stroke symptoms, not summarized as classical lacunar syndromes. We aimed to describe the spatial lesion distribution of acute supra- and infratentorial lacunar infarcts and their association with stroke symptoms in patients eligible for thrombolysis.

Methods

All patients enrolled in the WAKE-UP trial (efficacy and safety of magnetic resonance imaging [MRI]-based thrombolysis in wake-up stroke) were screened for lacunar infarcts on diffusion-weighted imaging (DWI). The relationship between the anatomical distribution of supra- and infratentorial lacunar infarcts, their demographic characteristics and acute stroke symptoms, defined by the National Institutes of Health Stroke Scale (NIHSS) score, were correlated and compared.

Results

Maps of lesion distribution from 224 lacunar infarct patients (76 [33.9%] females, mean age [standard deviation] of 63.4 [11.5] years) were generated using computational image mapping methods. Median infarct volume was 0.73 ml (interquartile range [IQR] 0.37–1.15 ml). Median NIHSS sum score on hospital arrival was 4 (IQR 3–6). 165 (73.7%) patients had lacunar infarcts in the supratentorial deep white or grey matter, while 59 (26.3%) patients had infratentorial lacunar infarcts. Patients with supratentorial lacunar infarcts presented with a significantly lower occurrence of deficits in the NIHSS items gaze (p < 0.001) and dysarthria (p = 0.008), but had more often a paresis of the left arm (p = 0.009) and left leg (p = 0.068) compared to patients with infratentorial infarcts.

Conclusions

The anatomical lesion distribution of lacunar infarcts reveals a distinct pattern and supports an association of localization with different stroke symptoms.

Trial registration

NCT01525290.

Frequent neurocognitive deficits after recovery from mild COVID-19

Neuropsychiatric complications associated with coronavirus disease 2019 caused by the Coronavirus SARS-CoV-2 (COVID-19) are increasingly appreciated. While most studies have focussed on severely affected individuals during acute infection, it remains unclear whether mild COVID-19 results in neurocognitive deficits in young patients. Here, we established a screening approach to detect cognitive deficiencies in post-COVID-19 patients. In this cross-sectional study, we recruited 18 mostly young patients 20-105 days (median, 85 days) after recovery from mild to moderate disease who visited our outpatient clinic for post-COVID-19 care. Notably, 14 (78%) patients reported sustained mild cognitive deficits and performed worse in the Modified Telephone Interview for Cognitive Status screening test for mild cognitive impairment compared to 10 age-matched healthy controls. While short-term memory, attention and concentration were particularly affected by COVID-19, screening results did not correlate with hospitalization, treatment, viremia or acute inflammation. Additionally, Modified Telephone Interview for Cognitive Status scores did not correlate with depressed mood or fatigue. In two severely affected patients, we excluded structural or other inflammatory causes by magnetic resonance imaging, serum and cerebrospinal fluid analyses. Together, our results demonstrate that sustained sub-clinical cognitive impairments might be a common complication after recovery from COVID-19 in young adults, regardless of clinical course that were unmasked by our diagnostic approach.

Intravenous alteplase for stroke with unknown time of onset guided by advanced imaging: systematic review and meta-analysis of individual patient data

BACKGROUND

Patients who have had a stroke with unknown time of onset have been previously excluded from thrombolysis. We aimed to establish whether intravenous alteplase is safe and effective in such patients when salvageable tissue has been identified with imaging biomarkers.

METHODS

We did a systematic review and meta-analysis of individual patient data for trials published before Sept 21, 2020. Randomised trials of intravenous alteplase versus standard of care or placebo in adults with stroke with unknown time of onset with perfusion-diffusion MRI, perfusion CT, or MRI with diffusion weighted imaging-fluid attenuated inversion recovery (DWI-FLAIR) mismatch were eligible. The primary outcome was favourable functional outcome (score of 0-1 on the modified Rankin Scale [mRS]) at 90 days indicating no disability using an unconditional mixed-effect logistic-regression model fitted to estimate the treatment effect. Secondary outcomes were mRS shift towards a better functional outcome and independent outcome (mRS 0-2) at 90 days. Safety outcomes included death, severe disability or death (mRS score 4-6), and symptomatic intracranial haemorrhage. This study is registered with PROSPERO, CRD42020166903.

FINDINGS

Of 249 identified abstracts, four trials met our eligibility criteria for inclusion: WAKE-UP, EXTEND, THAWS, and ECASS-4. The four trials provided individual patient data for 843 individuals, of whom 429 (51%) were assigned to alteplase and 414 (49%) to placebo or standard care. A favourable outcome occurred in 199 (47%) of 420 patients with alteplase and in 160 (39%) of 409 patients among controls (adjusted odds ratio [OR] 1·49 [95% CI 1·10-2·03]; p=0·011), with low heterogeneity across studies (I²=27%). Alteplase was associated with a significant shift towards better functional outcome (adjusted common OR 1·38 [95% CI 1·05-1·80]; p=0·019), and a higher odds of independent outcome (adjusted OR 1·50 [1·06-2·12]; p=0·022). In the alteplase group, 90 (21%) patients were severely disabled or died (mRS score 4-6), compared with 102 (25%) patients in the control group (adjusted OR 0·76 [0·52-1·11]; p=0·15). 27 (6%) patients died in the alteplase group and 14 (3%) patients died among controls (adjusted OR 2·06 [1·03-4·09]; p=0·040). The prevalence of symptomatic intracranial haemorrhage was higher in the alteplase group than among controls (11 [3%] vs two [<1%], adjusted OR 5·58 [1·22-25·50]; p=0·024).

INTERPRETATION

In patients who have had a stroke with unknown time of onset with a DWI-FLAIR or perfusion mismatch, intravenous alteplase resulted in better functional outcome at 90 days than placebo or standard care. A net benefit was observed for all functional outcomes despite an increased risk of symptomatic intracranial haemorrhage. Although there were more deaths with alteplase than placebo, there were fewer cases of severe disability or death.

FUNDING

None.

Higher white matter hyperintensity lesion load is associated with reduced long-range functional connectivity

Cerebral small vessel disease is a common disease in the older population and is recognized as a major risk factor for cognitive decline and stroke. Small vessel disease is considered a global brain disease impacting the integrity of neuronal networks resulting in disturbances of structural and functional connectivity. A core feature of cerebral small vessel disease commonly present on neuroimaging is white matter hyperintensities. We studied high-resolution resting-state EEG, leveraging source reconstruction methods, in 35 participants with varying degree of white matter hyperintensities without clinically evident cognitive impairment in an observational study. In patients with increasing white matter lesion load, global theta power was increased independently of age. Whole-brain functional connectivity revealed a disrupted network confined to the alpha band in participants with higher white matter hyperintensities lesion load. The decrease of functional connectivity was evident in long-range connections, mostly originating or terminating in the frontal lobe. Cognitive testing revealed no global cognitive impairment; however, some participants revealed deficits of executive functions that were related to larger white matter hyperintensities lesion load. In summary, participants without clinical signs of mild cognitive impairment or dementia showed oscillatory changes that were significantly related to white matter lesion load. Hence, oscillatory neuronal network changes due to white matter lesions might act as biomarker prior to clinically relevant behavioural impairment.

Neuropathology of patients with COVID-19 in Germany: a post-mortem case series

BACKGROUND

Prominent clinical symptoms of COVID-19 include CNS manifestations. However, it is unclear whether severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of COVID-19, gains access to the CNS and whether it causes neuropathological changes. We investigated the brain tissue of patients who died from COVID-19 for glial responses, inflammatory changes, and the presence of SARS-CoV-2 in the CNS.

METHODS

In this post-mortem case series, we investigated the neuropathological features in the brains of patients who died between March 13 and April 24, 2020, in Hamburg, Germany. Inclusion criteria comprised a positive test for SARS-CoV-2 by quantitative RT-PCR (qRT-PCR) and availability of adequate samples. We did a neuropathological workup including histological staining and immunohistochemical staining for activated astrocytes, activated microglia, and cytotoxic T lymphocytes in the olfactory bulb, basal ganglia, brainstem, and cerebellum. Additionally, we investigated the presence and localisation of SARS-CoV-2 by qRT-PCR and by immunohistochemistry in selected patients and brain regions.

FINDINGS

43 patients were included in our study. Patients died in hospitals, nursing homes, or at home, and were aged between 51 years and 94 years (median 76 years [IQR 70-86]). We detected fresh territorial ischaemic lesions in six (14%) patients. 37 (86%) patients had astrogliosis in all assessed regions. Activation of microglia and infiltration by cytotoxic T lymphocytes was most pronounced in the brainstem and cerebellum, and meningeal cytotoxic T lymphocyte infiltration was seen in 34 (79%) patients. SARS-CoV-2 could be detected in the brains of 21 (53%) of 40 examined patients, with SARS-CoV-2 viral proteins found in cranial nerves originating from the lower brainstem and in isolated cells of the brainstem. The presence of SARS-CoV-2 in the CNS was not associated with the severity of neuropathological changes.

INTERPRETATION

In general, neuropathological changes in patients with COVID-19 seem to be mild, with pronounced neuroinflammatory changes in the brainstem being the most common finding. There was no evidence for CNS damage directly caused by SARS-CoV-2. The generalisability of these findings needs to be validated in future studies as the number of cases and availability of clinical data were low and no age-matched and sex-matched controls were included.

FUNDING

German Research Foundation, Federal State of Hamburg, EU (eRARE), German Center for Infection Research (DZIF).

Polypharmacy, functional outcome and treatment effect of intravenous alteplase for acute ischaemic stroke

BACKGROUND AND PURPOSE

Polypharmacy is an important challenge in clinical practice. Our aim was to determine the effect of polypharmacy on functional outcome and treatment effect of alteplase in acute ischaemic stroke.

METHODS

This was a post hoc analysis of the randomized, placebo-controlled WAKE-UP trial of magnetic resonance imaging guided intravenous alteplase in unknown onset stroke. Polypharmacy was defined as an intake of five or more medications at baseline. Comorbidities were assessed by the Charlson Comorbidity Index (CCI). The primary efficacy variable was favourable outcome defined by a score of 0-1 on the modified Rankin Scale at 90 days. Logistic regression analysis was used to test for an association of polypharmacy with functional outcome, and for interaction of polypharmacy and the effect of thrombolysis.

RESULTS

Polypharmacy was present in 133/503 (26%) patients. Patients with polypharmacy were older (mean age 70 vs. 64 years; p < 0.0001) and had a higher score on the National Institutes of Health Stroke Scale at baseline (median 7 vs. 5; p = 0.0007). A comorbidity load defined by a CCI score ≥ 2 was more frequent in patients with polypharmacy (48% vs. 8%; p < 0.001). Polypharmacy was associated with lower odds of favourable outcome (adjusted odds ratio 0.50, 95% confidence interval 0.30-0.85; p = 0.0099), whilst the CCI score was not. Treatment with alteplase was associated with higher odds of favourable outcome in both groups, with no heterogeneity of treatment effect (test for interaction of treatment and polypharmacy, p = 0.29).

CONCLUSION

In stroke patients, polypharmacy is associated with worse functional outcome after intravenous thrombolysis independent of comorbidities. However, polypharmacy does not interact with the beneficial effect of alteplase.

Monitoring Intracranial Cerebral Hemorrhage Using Multicontrast Real-Time Magnetic Particle Imaging

Magnetic particle imaging (MPI) is an innovative radiation-free tomographic imaging method providing excellent temporal resolution, contrast, sensitivity, and safety. Mobile human MPI prototypes suitable for continuous bedside monitoring of whole-brain perfusion have been developed. However, for the clinical translation of MPI, a crucial gap in knowledge still remains: while MPI can visualize the reduction in blood flow and tissue perfusion in cerebral ischemia, it is unclear whether MPI works in intracranial hemorrhage. Our objective was to investigate the capability of MPI to detect intracranial hemorrhage in a murine model. Intracranial hemorrhage was induced through the injection of collagenase into the striatum of C57BL/6 mice. After the intravenous infusion of a long-circulating MPI-tailored tracer consisting of superparamagnetic iron oxides, we detected the intracranial hemorrhage in less than 3 min and could monitor hematoma expansion in real time. Multicontrast MPI can distinguish tracers based on their physical characteristics, core size, temperature, and viscosity. By employing in vivo multicontrast MPI, we were able to differentiate areas of liquid and coagulated blood within the hematoma, which could provide valuable information in surgical decision making. Multicontrast MPI also enabled simultaneous imaging of hemorrhage and cerebral perfusion, which is essential in the care of critically ill patients with increased intracranial pressure. We conclude that MPI can be used for real-time diagnosis of intracranial hemorrhage. This work is an essential step toward achieving the clinical translation of MPI for point-of-care monitoring of different stroke subtypes.

The ability of the eating assessment tool-10 to detect penetration and aspiration in Parkinson's disease

PURPOSE

Dysphagia is common in patients with Parkinson's disease (PD) and often leads to pneumonia, malnutrition, and reduced quality of life. This study investigates the ability of the Eating Assessment Tool-10 (EAT-10), an established, easy self-administered screening tool, to detect aspiration in PD patients. This study aims to validate the ability of the EAT-10 to detect FEES-proven aspiration in patients with PD.

METHODS

In a controlled prospective cross-sectional study, a total of 50 PD patients completed the EAT-10 and, subsequently, were examined by Flexible Endoscopic Evaluation of Swallowing (FEES) to determine the swallowing status. The results were rated through the Penetration-Aspiration Scale (PAS) and data were analyzed retrospectively.

RESULTS

PAS and EAT-10 did not correlate significantly. Selected items of the EAT-10 could not predict aspiration or residues. 19 (38%) out of 50 patients with either penetration or aspiration were not detected by the EAT-10. The diagnostic accuracy was established at only a sufficient level (AUC 0.65). An optimal cut-off value of ≥ 6 presented a sensitivity of 58% and specificity of 82%.

CONCLUSIONS

The EAT-10 is not suited for the detection of penetration and aspiration in PD patients. Therefore, it cannot be used as a screening method in this patient population. There is still a need for a valid, simple, and efficient screening tool to assist physicians in their daily diagnostics and to avoid clinical complications.